| Whole-plant and cellular bases for the salt tolerance of the tidal marsh dicot Kosteletzkya virginica were investigated by examining the effects of external NaCl-salinity on plants, cell suspension cultures, and plasma membrane fractions isolated from both roots and cell cultures.;Growth, ion and water relations, and (root) lipid content were measured in multiple harvests of roots, shoots, and individual leaves of plants grown hydroponically at several different salinity levels. Growth was inhibited only at NaCl concentrations exceeding 85 mol m;The rapid adjustment to and successful growth of cell suspension cultures of K. virginica to a range of salinity concentrations reflecting typical field levels demonstrated a strong cellular basis to the salt tolerance of this species. Tolerance varied according to growth phase, with early log phase cultures accumulating the greatest biomass. Proline content increased twenty-five fold in salinized versus unsalinized cultures, suggesting its use as a compatible solute. The correspondence observed between the salinity responses of whole plants and cell suspensions suggests that K. virginica cell cultures are a material well-suited for adoption in a crop improvement program and for the study of cellular tolerance mechanisms.;The chemical content of plasma-membrane enriched fractions isolated from salinized and unsalinized roots and cell suspension cultures were compared to determine whether membrane composition may be related to salinity adjustment. Membrane development was found to be more extensive in salt-treated tissues extracted both from K. virginica roots and cell suspension cultures. In addition, K. virginica plasma membranes were highly enriched in sterols (and had high sterol/phospholipid ratios), which were either maintained or elevated under saline conditions. |
